Before Fabriano: The Problem With Arab Paper
Paper reached Europe through Arab traders and the mills of Muslim Sicily and Spain during the 11th and 12th centuries. This early paper was made primarily from cotton and linen fibre, processed by hand with stone mortars and water-soaked retting — a slow, labour-intensive method that produced inconsistent pulp and sheets that varied significantly in thickness, opacity, and strength. The results were adequate for correspondence but unsuitable for the long-term archival documents that Italian civic and ecclesiastical administrations required in increasing quantities during the 13th century.
Fabriano's papermakers, working in mills established along the Giano River by the mid-1200s, did not abandon the basic principles of rag-pulp production. Instead, they systematically addressed each stage of the process where the Arab method produced unreliable results.
Stage One: Rag Collection and Sorting
The raw material for Fabriano paper was linen and cotton rags — worn clothing, remnant fabric from the town's wool and textile trades, and offcuts from tailors and weavers. Rag collection was organised through dedicated dealers who supplied mills on a regular basis. Quality sorting happened before any processing began: rags were separated by fibre type (linen producing stronger, longer-fibred pulp than cotton), by colour (white rags producing white paper without bleaching), and by degree of wear (more worn rags separated more easily into individual fibres).
Sorted rags were cut into small pieces and placed in stone or wooden pits with water, where they underwent retting — a controlled decomposition process lasting several days to several weeks, depending on the fibre and the season. Retting broke down the non-cellulose components of the fabric, leaving a loosened network of cellulose fibres that responded well to mechanical processing.
Stage Two: Hammer Milling
This was Fabriano's most consequential contribution to the production process. Earlier papermakers beat retted rags into pulp by hand using wooden pestles and stone or wooden mortars — a process that produced small batches of inconsistent quality and required continuous physical labour. The Fabriano solution was mechanical.
Adapting the trip-hammer technology already in use in the town's wool mills — which used water-powered cams to raise and drop heavy wooden hammers onto wool fleece — Fabriano craftsmen constructed dedicated papermaking hammer mills along the Giano River. The river's flow drove an undershot or overshot wheel, which turned a shaft fitted with eccentric cams. As the shaft rotated, the cams successively raised and released a row of heavy wooden hammers tipped with iron, driving them repeatedly into troughs containing the retted rags and a measured quantity of water.
The results were significantly better than hand-beating in three specific ways. First, the mechanical action was consistent: every hammer blow delivered the same force, producing fibres of more uniform length and distribution. Second, the capacity was orders of magnitude larger: a single mill with multiple hammers could process in a day what a team of hand-beaters required a week to produce. Third, the process ran continuously without fatigue — the water wheel operated as long as water flowed, regardless of the working hours of the mill staff.
By the mid-14th century, Fabriano's mills were producing approximately one million sheets annually. This figure, cited in historical accounts of the period, would have been impossible using hand-beating methods and explains why Fabriano paper could be sold at prices that undercut both parchment and imported Arab paper in Italian markets.
Stage Three: Vat and Mould Formation
The beaten pulp was transferred to large wooden vats filled with water, where it was maintained as a dilute suspension — typically one part fibre to several hundred parts water. A vatman stood at the vat with a wire-mesh mould framed in wood, dipping the mould into the suspension at a slight forward angle and then lifting it horizontally in a single continuous motion. The water drained through the mesh, leaving a thin, even layer of interlocked fibres across the mould surface.
The skill of the vatman determined the consistency of the sheet. Too fast a lift produced thick edges and a thin centre; too slow allowed the fibres to begin settling non-uniformly. Experienced vatmen developed a standardised motion — described in 18th-century French papermaking manuals as "the shake," a brief lateral oscillation of the mould immediately after lifting — that interlocked the fibres in multiple directions and strengthened the finished sheet.
Stage Four: Couching, Pressing, and Drying
Once the initial water had drained, the newly formed wet sheet was transferred from the mould onto a piece of woven wool felt — a process called couching. Successive sheets were built up in a post, alternating paper and felt, until a manageable stack had accumulated. The post was then placed in a hydraulic or screw press and squeezed to remove the bulk of the remaining water, reducing the water content of each sheet by roughly half.
The pressed sheets were separated from the felt and hung individually on ropes in drying rooms — typically the upper stories of the mill building, where heat rose from the production floor below and airflow could be regulated by adjusting wooden shutters. Drying took several hours to a full day depending on temperature and humidity. Sheets dried too quickly became brittle; sheets dried too slowly were prone to mould.
Stage Five: Animal Gelatine Sizing
Unsized paper — paper that has not been treated after drying — absorbs ink immediately on contact, spreading through the fibres in all directions and producing blurred, feathered lines unsuitable for precise writing. Arab-produced paper was sized with starch paste, which provided some resistance to ink absorption but degraded over time and provided poor resistance to moisture.
Fabriano papermakers replaced starch sizing with animal gelatine. The raw material was the waste product of the town's leather tanning industry — skin, hooves, and connective tissue offcuts that were otherwise discarded. Boiled in water and reduced, these materials produced a clear gelatine that, when applied to dried paper sheets in a heated bath and allowed to dry again, formed a continuous film across the surface of the sheet. The film sealed the fibres against ink spread, gave the paper a slightly polished surface that held fine writing lines cleanly, and — critically — provided significantly better resistance to moisture and biological degradation than starch.
It was this gelatine-sized paper that overcame the concerns expressed in Frederick II's 1231 decree. Chancellery tests conducted in Italian cities during the late 13th century confirmed that gelatine-sized Fabriano paper, stored under normal archival conditions, retained its writing surface and structural integrity for decades — a performance comparable to parchment at a fraction of the cost.
Legacy in European Paper Production
The sequence of techniques Fabriano developed — mechanical hammer milling, consistent vat formation, hydraulic pressing, and gelatine sizing — became the standard method for European paper production within a century of their introduction. Mills established in France, Germany, the Netherlands, and England during the 14th and 15th centuries adopted the Fabriano process either through direct knowledge transfer (Italian papermakers were employed at several early French mills) or through reverse engineering of Fabriano paper itself.
The handmade paper process remained essentially unchanged until the introduction of the Fourdrinier continuous-wire papermaking machine in 1805 and the Hollander beater in the late 17th century, which replaced hammer mills in most industrial operations. Both these later innovations were improvements in mechanical efficiency, not in the underlying chemistry or fibre science that Fabriano had established.